Around the world on a solar airplane, flying day and night without fuel to promote clean technologies!

1. PARTNERS’
DEVELOPMENTS
LEGACY

2. 1
PARTNERS’ DEVELOPMENTS
LEGACY
By bringing companies together to work on a common enterprise,
Solar Impulse highlighted the beneficial impact of team-work in
overcoming hurdles in order to find innovative solutions.
Solar Impulse’s attempt to fly around the world powered only by solar
energy set a goal many thought “impossible” and placed the bar very
high. A family group of partners took up the challenge to invent new
paradigms and find the answers to problems that until now had remained
unsolvable. They combined their very diverse backgrounds and specialist
talents to build bridges between various areas of expertise and push
back the frontiers of technological knowledge.
These inventive, energy-efficient solutions are emerging today from
research centers to arrive in our daily lives. They are already used in
electricity networks, house insulation, food conservation, and vehicles,
as well as industrial processes.

3. 2
ENERGY STORAGE
Microgrid installations
ABB
SHARED EXPERIENCE WITH SOLAR IMPULSE
To be able to fly day and night, Solar Impulse relies on batteries that store
the energy collected during the day and use it to power its engines during
the night. The same requirement exists for introducing renewable energy
into fossil-fuel based power-generation systems. Batteries are needed
to even out the production profile i.e. to temporarily to store the excess
electricity produced and discharge it to prevent power outages and damage
to the network.
APPLICATION ON THE GROUND
Microgrid installations are commercialised by ABB to upgrade existing diesel-
based off-grid systems with renewable energies in remote communities that
often rely solely on imported fuels (which are both expensive and polluting).
These systems ensure a clean and stable electricity supply to populations.
Positive impact
The integration of renewables
with microgrid installations can
replace between 40 and 240 GW
of power capacity originally
produced with diesel. In some
cases, 400,000 litres of fuel can
be spared annually, thereby
avoiding 1,100 tons of CO2
emissions.

4. 3
Special binder for batteries
Solvay
ENERGY STORAGE
CHALLENGES OVERCOME WITH SOLAR IMPULSE
Important challenges had to be overcome to build a sufficient and reliable
battery storage system for Solar Impulse – a system the plane could rely on
for power during the night until the sun rises: maximization of the batteries’
lightness, energy density and durability.
SOLUTION DEVELOPED FOR SOLAR IMPULSE
The Solef PVDF binder developed by Solvay was used to offer optimal binding
for Solar Impulse’s batteries’ electrodes. It helps to reduce their weight to a
minimum while improving the chemical stability of their cells; i.e. it increases
the number of charge and discharge cycles the battery can withstand and
thereby increases its lifetime.
APPLICATION ON THE GROUND
Electric cars
This technology can be applied to upgrade electric cars’ batteries.
Grid storage systems
It can also be applied for grid electricity storage.
Positive impact
Electric cars
This binder could improve the
range of a standard electric
car by 10 km, and provided
the other materials do not
downgrade, could increase
their batteries’ lifetime by 20%.
Grid storage systems
The use of this special binder
in batteries for grid electricity
storage would allow
stabilization of distribution
networks in regions with a
high intermittent PV power
concentration.

5. 4
MOTORS’ EFFICIENCY
Additive to upgrade motors’ lubricant
Solvay
CHALLENGES OVERCOME WITH SOLAR IMPULSE
In order to make maximum use of the energy collected through the solar
cells, the efficiency and durability of the solar airplane’s motors had to
be optimized.
SOLUTION DEVELOPED WITH SOLAR IMPULSE
The Fomblin PFPE lubricant additive developed by Solvay enhances the
anti-wear and anti-rust properties of lubricants used in Solar Impulse’s
electric motors. This technology increases the lubricant’s operating life,
thereby reducing the need for maintenance of rotors and stators in the
plane’s engines.
APPLICATIONS ON THE GROUND
All engines
This additive can be applied to upgrade the lubricants of any engine.
Positive impact
It can decrease mechanical
losses by 50% in motors, triple
a car’s engine fuel efficiency –
decreasing by nearly 70% the
annual fuel cost of driving a
gasoline car.

6. 5
MOTORS’ EFFICIENCY
Smart sensors to increase motors’ efficiency
ABB
Machine room-less elevators
with gearless motors
SCHINLDER
SHARED EXPERIENCE WITH SOLAR IMPULSE
Thanks to the sensors that collect information on the plane’s systems (speed,
battery charge level, bank angle), Solar Impulse’s engineers can analyse
hundreds of data before and during the flights to allow optimal functioning
and ensure endurance through the nights. The same approach can be
followed for optimizing the efficiency of industrial electric motors.
APPLICATION ON THE GROUND
The smart sensor technologies developed by ABB enable industrial motors
to provide conditions and performance data that can be analysed to optimize
their energy use and increase industrial efficiency, in other words boost
productivity and reduce costs significantly.
Positive impact
Electric motor energy efficiency
could increase by 10% and it’s
been worked out that if all
industrial electric motors
used such sensors to collect
information, 616 billion kWh
of electricity could be saved
every year.
SHARED EXPERIENCE WITH SOLAR IMPULSE
In Solar Impulse, the electricity produced by the solar cells has to be used
as efficiently as possible to drive electromagnets on the plane’s motors.
These motors had to meet stringent requirements of lightness and efficiency
to minimize losses. The same requirements apply for elevators’ motors.
APPLICATION ON THE GROUND
The machine room-less elevators commercialised by Schindler carry
high efficiency AC gearless permanent magnets motors to lift people to
their destinations.
Positive impact
This technology allows elevators
to be 60% more energy efficient
compared to hydraulic systems.
Also, it needs fewer moving
parts and is quieter, therefore
increasing reliability and comfort.

7. 6
SMART ENERGY USE
Regenerative drives for elevators
Schindler
SHARED EXPERIENCE WITH SOLAR IMPULSE
In Solar Impulse, every system was engineered to optimize energy use
and pass it on when and where it is most needed, offering flexibility in case
of emergency situations. For instance, if one motor fails, the power can
be redistributed amongst the remaining engines so that the plane keeps
in balance and remains in the air. The same mindset can be applied for
sustainable transportation.
APPLICATION ON THE GROUND
The innovative Regenerative Drives technology developed by Schindler
allows surplus energy to be sent back from the elevator to the building’s
power grid allowing other building consumers to make use of this not
needed energy.
Positive impact
This technology reduces net
power usage and utility bills
(between 30 and 55% reduction
in annual power costs).
Additionally, because heat
generation can be cut by up to
50%, less cooling is required
in the elevator machine room.

8. 7
SMART ENERGY USE
Two-speed and Auto Start/Stop
technologies for escalators
Schindler
Destination-dispatch system for elevators
Schindler
SHARED EXPERIENCE WITH SOLAR IMPULSE
During the night, the solar airplane adopts a descending profile to minimise
its energy consumption by gliding. This way energy is saved at the relevant
time and the plane can rely on batteries to make it through the night. This
approach can be followed to save energy in escalators during off-peak hours.
APPLICATION ON THE GROUND
The variable-speed escalator technologies developed by Schindler have
an auto start/stop mode and a two-speed control system that allow saving
energy during off-peak hours by reducing the speed or stopping the elevator
when no one is using it.
Positive impact
In a typical office building, the
auto start/stop technology
enables an energy use
reduction of up to 52%. In turn,
the two-speed control system
offers an average energy
saving of 14%.
SHARED EXPERIENCE WITH SOLAR IMPULSE
Before a flight, Solar Impulse engineers perform simulations to find the best
- i.e. the most energy-efficient - route for the airplane to follow. That process
can also be done for elevators to determine the most energy-efficient way of
bringing people to the requested floor.
APPLICATION ON THE GROUND
The destination-dispatching system PORT (Personal Occupant Requirement
Terminal) developed by Schindler can find the 1 in 7 trillion ride that is “right”
for each user of building elevators.
Positive impact
This technology can improve
traffic flow, reduce wait time
and the number of intermediate
stops, to make the elevator
run at the pinnacle of its
performance.

9. 8
INNOVATIVE MATERIALS
Composites to reduce the structure weight
Solvay
CHALLENGES OVERCOME WITH SOLAR IMPULSE
The use of low weight unidirectional and fabric composites allows the flexibility
to design and manufacture very lightweight components which is a key benefit
to the Solar Impulse project.
SOLUTION DEVELOPED WITH SOLAR IMPULSE
The composite materials developed by Solvay, have been used to build the
Solar Impulse structure.
• A structural out of autoclave prepreg is used to manufacture the large wing
spar honeycomb sandwich structure and other composite parts.
• A low temperature out of autoclave tooling prepreg is used to manufacture
the large composite mould tools needed to form the wing composite skins
on Solar Impulse.
APPLICATION ON THE GROUND
Aerospace & automotive industries
The aerospace industry is currently the biggest user of these composites,
while the automotive industry is massively increasing its lightweighting efforts.
Already used in Formula 1 and luxury cars, composites should find their way
into other automotive segments in the near future.
Others
These composites are particularly suited to the marine and industrial markets
(e.g. marine hulls, wind turbine blade and spars, train doors, bullet proof vest,
sporting goods, etc)
Positive impact
Aerospace & automotive industries
These composites reduce the
weight and increase the fuel
efficiency without compromising
structural strength or safety.
Others
Composites are strong yet
flexible, offer additional
properties such as corrosion
resistance or ballistic properties
and enable the manufacture of
complex parts for applications
where lightweighting is a must.

10. 9
INNOVATIVE MATERIALS
Polycarbonate window
with glass-like appearance
Covestro
Polyurethane foam insulation
Covestro
CHALLENGES OVERCOME WITH SOLAR IMPULSE
The cockpit window of Solar Impulse had to be very light and resistant
to extreme conditions while offering optimal transparency properties.
SOLUTION DEVELOPED FOR SOLAR IMPULSE
The Transparent polycarbonate sheeting developed by Covestro has
mechanical properties superior to that of glass, a glass-like appearance,
and improved safety functions such as anti-fogging properties thanks
to a special coating.
APPLICATION ON THE GROUND
Car windows
The automotive industry is seeking car windows that are lighter yet more
resistant.
Solar dryers
The outstanding properties of this sheeting are being put to good use in
solar dryers for the fruit and vegetable crops of smallholder farmers in
South-East Asia.
Positive impact
Car windows
The significantly reduced
weight of windows could allow
more batteries to be installed
in electric cars.
Solar dryers
This technology can help avoid
food wastage and creates
economic benefits for under-
served communities.
CHALLENGES OVERCOME WITH SOLAR IMPULSE
Insulation in the Solar Impulse cockpit and gondolas had to meet the challenges
of lightness, resistance and efficiency to protect the pilot and the plane’s
batteries from extreme conditions during flight, given the absence of a heating
system on board.
SOLUTION DEVELOPED FOR SOLAR IMPULSE
The polyurethane foam developed by Covestro has 40% smaller pores and
offers a higher rigidity and structural strength while remaining lightweight.
APPLICATION ON THE GROUND
Home insulation
This material can be used in prefabricated panels to build affordable homes.
Food storage
It can also be applied for cheap food storage solutions in under-served markets.
Positive impact
Home insulation
This technology could save
close to 20% on yearly energy
bills compared to standard
insulation solutions.
Food storage
This solution has a positive social
and environmental impact in
developing countries where food
is scarce and food conservation
is a major problem.